21457011 has 4 divisors (see below), whose sum is σ = 28609352. Its totient is φ = 14304672.

The previous prime is 21456989. The next prime is 21457021. The reversal of 21457011 is 11075412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21457011 - 2⁵ = 21456979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21457021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3576166 + ... + 3576171.

It is an arithmetic number, because the mean of its divisors is an integer number (7152338).

Almost surely, 2^21457011 is an apocalyptic number.

21457011 is a deficient number, since it is larger than the sum of its proper divisors (7152341).

21457011 is an equidigital number, since it uses as much as digits as its factorization.

21457011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7152340.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 21457011 is about 4632.1713051225. The cubic root of 21457011 is about 277.8794354972.

The spelling of 21457011 in words is "twenty-one million, four hundred fifty-seven thousand, eleven".